Product Documentation for
Devicescape Secure Wireless Client

API Reference Documentation for Devicescape Secure Wireless Client

Structure of the Source Code

The Devicescape Secure Wireless Client (wpa_supplicant) implementation is divided into number of independent modules. Core code includes functionality for controlling the network selection, association, and configuration. Independent modules include WPA code (key handshake, PMKSA caching, pre-authentication), EAPOL state machine, and EAP state machine and methods. In addition, there are number of separate files for generic helper functions.

Both WPA and EAPOL/EAP state machines can be used separately in other programs than wpa_supplicant. As an example, the included test programs eapol_test and preauth_test are using these modules.

Driver interface API is defined in driver.h and all hardware/driver dependent functionality is implemented in driver_*.c.

wpa_supplicant Core Functionality

wpa_supplicant.c Program initialization, main control loop

main.c main() for UNIX-like operating systems and MinGW (Windows); this uses command line arguments to configure wpa_supplicant

events.c Driver event processing; wpa_supplicant_event() and related functions

wpa_supplicant_i.h Internal definitions for wpa_supplicant core; should not be included into independent modules

wpa_supplicant.h Definitions for driver event data and message logging

Generic Helper Functions

wpa_supplicant uses generic helper functions some of which are shared with with hostapd. The following C files are currently used:

eloop.c and eloop.h Event loop (select() loop with registerable timeouts, socket read callbacks, and signal callbacks)

common.c and common.h Common helper functions

defs.h Definitions Shared by Multiple Files

l2_packet.h, l2_packet_linux.c, and l2_packet_pcap.c Layer 2 (link) access wrapper (includes native Linux implementation and wrappers for libdnet/libpcap). A new l2_packet implementation may need to be added when porting to new operating systems that are not supported by libdnet/libpcap. Makefile can be used to select which l2_packet implementation is included. l2_packet_linux.c uses Linux packet sockets and l2_packet_pcap.c has a more portable version using libpcap and libdnet.

pcsc_funcs.c and pcsc_funcs.h Wrapper for PC/SC lite SIM and smart card readers

priv_netlink.h Private version of netlink definitions from Linux kernel header files; this could be replaced with C library header file once suitable version becomes commonly available

version.h Version number definitions

wireless_copy.h Private version of Linux wireless extensions definitions from kernel header files; this could be replaced with C library header file once suitable version becomes commonly available

Cryptographic Functions

md5.c and md5.h MD5 (replaced with a crypto library if TLS support is included) HMAC-MD5 (keyed checksum for message authenticity validation)

rc4.c and rc4.h RC4 (broadcast/default key encryption)

sha1.c and sha1.h SHA-1 (replaced with a crypto library if TLS support is included) HMAC-SHA-1 (keyed checksum for message authenticity validation) PRF-SHA-1 (pseudorandom (key/nonce generation) function) PBKDF2-SHA-1 (ASCII passphrase to shared secret) T-PRF (for EAP-FAST) TLS-PRF (RFC 2246)

aes_wrap.c, aes_wrap.h, aes.c AES (replaced with a crypto library if TLS support is included), AES Key Wrap Algorithm with 128-bit KEK, RFC3394 (broadcast/default key encryption), One-Key CBC MAC (OMAC1) hash with AES-128, AES-128 CTR mode encryption, AES-128 EAX mode encryption/decryption, AES-128 CBC

crypto.h Definition of crypto library wrapper

crypto.c Wrapper functions for libcrypto (OpenSSL)

crypto_gnutls.c Wrapper functions for libgcrypt (used by GnuTLS)

ms_funcs.c and ms_funcs.h Helper functions for MSCHAPV2 and LEAP

tls.h Definition of TLS library wrapper

tls_none.c Dummy implementation of TLS library wrapper for cases where TLS functionality is not included.

tls_openssl.c TLS library wrapper for openssl

tls_gnutls.c TLS library wrapper for GnuTLS

Configuration

config_ssid.h Definition of per network configuration items

config.h Definition of the wpa_supplicant configuration

config.c Configuration parser and common functions

config_file.c Configuration backend for text files (e.g., wpa_supplicant.conf)

Control Interface

wpa_supplicant has a control interface that can be used to get status information and manage operations from external programs. An example command line interface (wpa_cli) and GUI (wpa_gui) for this interface are included in the wpa_supplicant distribution.

ctrl_iface.c and ctrl_iface.h wpa_supplicant-side of the control interface

wpa_ctrl.c and wpa_ctrl.h Library functions for external programs to provide access to the wpa_supplicant control interface

wpa_cli.c Example program for using wpa_supplicant control interface

WPA Supplicant

wpa.c and wpa.h WPA state machine and 4-Way/Group Key Handshake processing

preauth.c and preauth.h PMKSA caching and pre-authentication (RSN/WPA2)

wpa_i.h Internal definitions for WPA code; not to be included to other modules.

EAP Peer

EAP Peer Implementation is a separate module that can be used by other programs than just wpa_supplicant.

eap.c and eap.h EAP state machine and method interface

eap_defs.h Common EAP definitions

eap_i.h Internal definitions for EAP state machine and EAP methods; not to be included in other modules

eap_sim_common.c and eap_sim_common.h Common code for EAP-SIM and EAP-AKA

eap_tls_common.c and eap_tls_common.h Common code for EAP-PEAP, EAP-TTLS, and EAP-FAST

eap_tlv.c and eap_tlv.h EAP-TLV code for EAP-PEAP and EAP-FAST

eap_ttls.c and eap_ttls.h EAP-TTLS

eap_pax.c, eap_pax_common.h, eap_pax_common.c EAP-PAX

eap_psk.c, eap_psk_common.h, eap_psk_common.c EAP-PSK (note: this is not needed for WPA-PSK)

eap_sake.c, eap_sake_common.h, eap_sake_common.c EAP-SAKE

eap_gpsk.c, eap_gpsk_common.h, eap_gpsk_common.c EAP-GPSK

eap_aka.c, eap_fast.c, eap_gtc.c, eap_leap.c, eap_md5.c, eap_mschapv2.c, eap_otp.c, eap_peap.c, eap_sim.c, eap_tls.c Other EAP method implementations

config_types.h and hostapd.h Minimal version of hostapd header files for eapol_test

eapol_test.c Standalone EAP testing tool with integrated RADIUS authentication client

preauth_test.c Standalone RSN pre-authentication tool

wpa_passphrase.c WPA ASCII passphrase to PSK conversion

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© 2005 Devicescape Software, Inc. All Rights Reserved.

Product Documentation for Devicescape Secure Wireless Client

API Reference Documentation for Devicescape Secure Wireless Client

Product Documentation for
Devicescape Secure Wireless Client